WO2006051934A1

WO2006051934A1 - Surface magnet type motor, surface magnet type motor manufacturing method, and internal combustion engine using the surface magnet type motor

Info

Publication number: WO2006051934A1
Application number: PCT/JP2005/020787
Authority: WO
Inventors: Tomoyuki Maeda
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2004-11-15
Filing date: 2005-11-08
Publication date: 2006-05-18
Also published as: US7830058B2; EP2637288B1; EP1826884A4; EP2637288A3; EP2637288A2; EP1826884B1; JP4400425B2; CN101057382B; CN101057382A; EP1826884A1; US20080111435A1; JP2006141164A

Abstract

A surface magnet type motor (10) has a magnet (16) on the surface of a rotor (15). The motor has an anti-scattering tube (17) of a cylindrical shape having a length greater than the axial direction length of the magnet (16) arranged on the rotor (15) and containing the magnet with a pressure so as to prevent scattering of the magnet. The motor also has a stress mitigation unit for mitigating the stress caused at the end portion of the magnet (16) contained in the anti-scattering tube (17) with a pressure.

Description

Surface magnet type motor, manufacturing method of surface magnet type motor,

And internal combustion engines with surface magnet motors

The present invention relates to a surface magnet type motor using a magnet for a rotor, and more particularly to an anti-scattering tube for preventing the scattering of magnets. Background art

Conventionally, there has been known a surface magnet type motor provided with a rotor having a magnet arranged on the outer peripheral surface of a rotating shaft. In this type of motor, in order to prevent damage and scattering of the magnet due to centrifugal force when the rotor rotates at high speed, a nonmagnetic anti-scattering pipe is provided on the outer periphery of the magnet.

Fixing of the anti-scattering tube of such an electric motor is generally performed by pressing a magnet into the inner cylinder of the anti-scattering tube. By doing this, it is believed that the magnet can be held under strong pressure and breakage or scattering of the magnet due to centrifugal force can be prevented (for example, JP-A Nos. 2 0 0 1-2 5 1 5 3, 2 0 0 1-2 1 8 4 0 3)).

In order to cope with high-speed rotation and realize use with high centrifugal force and a wide operating temperature in a powerful motor, the press-in allowance between the anti-scattering tube and the magnet is increased to make the force more strong. Need to hold the magnet. By increasing the press-in allowance while doing so, the magnet may be damaged rather than the press-in pipe.

Such stress on the magnet may lead to breakage under the influence of the centrifugal force applied during operation of the surface magnet type motor, even if the phenomenon of breakage at the time of assembly does not occur. In particular, when using such a motor for assisting the turbine shaft of a turbocharger rotating at a high speed of one hundred to twenty thousand rpm, it is necessary to guarantee the strength to the operating limit of the turbine shaft. Therefore, there is a need for a structure and a manufacturing method that relieves the stress generated in such magnets. Disclosure of the invention

In view of these problems, the present invention has an object to provide a surface magnet type motor provided with an anti-scattering tube for reducing stress generated in a magnet by press fitting, a manufacturing method, and an internal combustion engine provided with a surface magnet type motor. Do.

In view of the above problems, the surface magnet type motor according to the present invention adopts the following method. That is, it is a surface magnet type motor having a magnet on the surface of the rotor, which is formed in a cylindrical shape longer than the axial length of the magnet provided on the rotor, and the magnet is press-fitted therein to make the magnet The gist is that a shatterproof tube is provided to prevent shattering, and a stress relief section is provided to relieve the stress generated at the end of the magnet pressed into the shatterproof tube.

According to the surface magnet type electric motor of the present invention, the end portion of the anti-scattering tube which is longer than the magnet is provided with a stress relaxation portion which relieves the stress generated at the end of the magnet by pressing the magnet into the anti-scattering tube. That is, it is possible to form the rotor in a state in which the stress applied to the end of the magnet is reduced by press-fitting. Therefore, it is possible to suppress the breakage of the magnet at the time of press-fitting, at the time of assembling the rotor after press-fitting, or at the time of using it as an electric motor.

The stress relieving portion of the surface magnet type motor having the above-mentioned configuration is a part of the anti-scattering tube, and is provided on a protruding portion respectively protruding from both end faces of the pressed-in magnet. It can be a shape that suppresses the difference in displacement in the radial direction that occurs in the part excluding the part.

According to the surface magnet type motor with force, a projection suppressing portion of the anti-scattering tube is provided with a shape for suppressing the difference in the inner diameter direction, and this is used as a stress relieving portion. That is, the difference between the displacement in the inward direction that occurs in the part excluding the projecting part due to the press-in of the magnet and the displacement in the inward direction of the projecting part that is affected by the press-in of the magnet into this part is suppressed. Therefore, it is possible to suppress large deformation of a part of the anti-scattering tube due to press-fitting of the magnet. As a result, the stress applied to the end of the magnet due to the reaction force due to the deformation of the anti-scattering tube can be reduced.

The stress relieving portion of the surface magnet type motor having the above configuration may have a shape that suppresses the difference by making the protruding portion lower in rigidity than the portion excluding the protruding portion. According to the surface magnet type motor with force, a low rigidity shape is provided at the protruding part of the anti-scattering tube, and this is used as a stress relief part. Since the protruding part has low rigidity, it is easily deformed under the influence of the magnet's pressure. In other words, the presence of the magnet inside makes it easy to be influenced by the part excluding the protruding part that expands in diameter. Therefore, it is possible to reduce the stress applied to the end of the magnet by suppressing the difference in displacement in the radial direction between the protruding part and the part excluding the protruding part after the magnet is pressed.

The shape suppressing the difference of the surface magnet type motor having the above-mentioned configuration may be made low in rigidity by making the protruding part thinner than the part excluding the protruding part.

According to the surface magnet type motor with pressure, the protruding part is thinner than the part excluding the protruding part. For example, as a thin-walled shape, the anti-scattering tube is formed in a stepped cylindrical shape. In this way, a low rigidity shape can be realized with a relatively simple shape, and a stress relaxation portion can be easily provided.

The shape that suppresses the difference between the surface magnet type motor having the above configuration may be made low in rigidity by forming a notch of a predetermined depth in the outer cylinder of the protruding portion. According to the surface magnet type motor with force, a notch is formed in the outer cylinder of the protruding part of the anti-scattering tube. Therefore, a low rigidity shape can be realized by relatively easy processing.

The stress relieving portion of the surface magnet type motor having the above configuration has a shape in which the difference is suppressed by making the cylindrical inner diameter of the protruding portion larger than the cylindrical inner diameter of the portion excluding the protruding portion. It is good also as what to do.

According to such a surface magnet type motor, the cylindrical inner diameter of the protruding portion is expanded in a tapered manner. That is, the inner diameter of the end of the protruding portion is formed in advance. Therefore, even if the inside diameter of the part excluding the protruding part is expanded by the press-in of the magnet, the inside diameter of the protruding part is expanded in advance, so that the difference in the displacement in the inner diameter direction of both after the press-in is suppressed. Can. As a result, the stress applied to the end of the magnet can be reduced.

The stress relieving portion of the surface magnet type motor having the above configuration may have a shape in which the protruding portion is expanded in a trumpet shape to suppress the difference. According to such a surface magnet type motor, both the inner diameter and the outer diameter of the protruding portion form a trumpet-shaped enlarged shape toward the end. Therefore, the difference between the displacement in the inner diameter direction of the two after the press-in can be suppressed by the protruding portion which is enlarged in advance. Furthermore, it is possible to form a shape that suppresses the difference in displacement in the inner diameter direction without significantly reducing the rigidity of the protruding portion.

The surface magnet type motor having the above configuration is provided with an assembly flange between the bearing attached to the rotary shaft and each end face of the magnet, and the stress relief portion protrudes from each end face of the pressed-in magnet. The protrusion is provided at a contact portion where the protrusion which is a part of the anti-scattering tube and the assembly flange make contact with each other, and an external force in the rotational axis direction is applied from both outer sides of the assembly flange. It can be made to be a shape which suppresses the difference of displacement of an internal diameter direction which arises in a portion and a portion except the projection part.

According to such a surface magnet type motor, the shape of the contact portion is formed into a shape that suppresses the difference in the displacement in the inner diameter direction of the anti-scattering tube after press-fitting by an external force, and this is used as a stress relaxation portion. That is, external force from both sides of the assembly flange is applied to the splash prevention tube which has already caused the displacement difference in the inner diameter direction by press-fitting the magnet, thereby suppressing the difference in displacement in the inner diameter direction. Therefore, the stress applied to the end of the magnet can be reduced.

The contact portion of the surface magnet type motor having the above configuration may be shaped so as to convert the external force from the assembly flange into an axial force applied to the outer peripheral side than the inner periphery of the anti-scattering tube.

According to such a surface magnet type motor, the external force transmitted to the contact portion is an axial force applied to the outer peripheral side of the anti-scattering tube. For example, if the change in inside diameter of the protruding part due to the press-in of the magnet is smaller than the change in inside diameter of the part excluding the protruding part, the anti-scattering tube after press-fitting has a shape where the protruding part is bent inward. By applying an axial force to the outer peripheral side of the anti-scattering tube, the force acts in the direction to improve the inward bending and sag, and it is possible to suppress the difference in displacement in the inner diameter direction.

In the surface magnet type motor having the above configuration, the contact portion of the anti-scattering tube may be formed in a convex shape in contact with the assembly flange at the outer peripheral end face of the anti-scattering tube. According to such a surface magnet type motor, a convex shape for transmitting an external force to the outer peripheral side of the anti-scattering tube is formed at the contact portion of the anti-scattering tube, and this is used as a stress relief portion. That is, a convex shape is provided only at the contact portion on the side of the anti-scattering tube. Therefore, it is necessary to shape the flange side for assembly into a special shape.

In the surface magnet type motor having the above configuration, the contact portion of the assembly flange may be formed in a convex shape in contact with the outer peripheral end surface of the anti-scattering tube.

According to such a surface magnet type motor, a convex shape for transmitting an external force to the outer peripheral side of the anti-scattering tube is formed at the contact portion of the assembly flange, and this is used as a stress relieving portion. That is, a convex shape is provided only on the contact portion on the assembling flange side. Therefore, it is not necessary to form the anti-scattering tube side into a special shape.

In the surface magnet type motor having the above configuration, the contact portion of the anti-scattering tube is formed in a cylindrical shape which is smaller than the cylindrical outer diameter of the portion excluding the protruding portion, and the entire anti-scattering tube has a stepped cylindrical shape. The contact portion of the assembly flange may be formed in contact with the shoulder portion of the stepped cylindrical portion.

According to the surface magnet type motor with force, a small cylindrical portion with a stepped cylindrical shape is a contact portion of the anti-scattering tube, and a shape in contact with the stepped shoulder portion is a contact portion of the assembly flange. Therefore, in addition to the effect of lowering the rigidity, an axial force can be applied to the outer peripheral side of the anti-scattering tube via the stepped shoulder, and the difference in displacement in the inner diameter direction can be reduced. As a result, the stress applied to the end of the magnet can be reduced.

The contact portion of the surface magnet type motor having the above configuration may be shaped so as to convert the external force from the assembly flange into a force in the direction in which the inner diameter of the projecting portion is expanded.

According to the surface magnet type motor, the external force transmitted to the contact portion is a force to expand the inner diameter of the protruding portion of the anti-scattering tube. For example, in the case where the change in inner diameter of the protruding part due to the press-in of the magnet is smaller than the change in inner diameter of the part excluding the protruding part, the anti-scattering tube after the press-in has a shape in which the protruding part is bent inward. By applying an external force to such an anti-scattering tube, the inner diameter of the protruding portion can be expanded, and the difference in displacement in the inner diameter direction can be suppressed.

In the surface magnet type motor having the above configuration, the contact portion of the anti-scattering tube is protruded The inner diameter of the portion may be formed in a tapered shape which is enlarged with respect to the inner diameter of the portion excluding the projecting portion, and the contact portion of the assembly flange may be formed in a shape engaged in the tapered shape.

According to such a surface magnet type motor, the inner diameter is tapered to form the contact portion of the anti-scattering tube, and the contact portion of the assembly flange is formed in a shape to be engaged with this, and the assembly flange is formed. Insert the contact part of the inside of the anti-scattering tube. When an external force is applied from the outside of the assembly flange having such a contact portion, the inner diameter of the end of the anti-scattering tube is expanded due to the action of the taper shape. Therefore, it is possible to suppress the difference in the displacement in the radial direction of the anti-scattering tube caused by the press-fitting of the magnet.

In the surface magnet type motor having the above-mentioned configuration, the contact portion of the assembly flange may be formed into a cylindrical shape which has substantially the same outer diameter as the magnet and which can be press-fit into the projection of the anti-scattering tube.

According to the surface magnet type motor with force, assembly flanges are pressed into the protruding part of the anti-scattering tube. Therefore, the inner diameter of the projecting portion is also expanded substantially in the same manner as the inner diameter of the portion excluding the projecting portion, and it is possible to suppress the difference in displacement in the radial direction over the entire length of the anti-scattering tube.

The manufacturing method corresponding to the surface magnet type motor according to the present invention is a method of manufacturing a surface magnet type motor having a magnet on the surface of the rotor, and (a) covering the surface of the magnet of the rotor to scatter the magnet Forming an anti-scattering tube in a cylindrical shape longer than the axial length of the magnet; (b) a stress relaxation portion for relieving stress generated at the end of the magnet housed inside the anti-scattering tube And a step of press-fitting the magnet into the inside of the anti-scattering tube.

According to this manufacturing method, the magnet is pressed into the inside of the anti-scattering tube, while forming a stress relaxation portion that relieves the stress generated at the end of the magnet. That is, the stress relieving portion is configured before press-in of the magnet, or is configured after the press-in of the magnet. Therefore, the stress generated in the magnet is relieved, and a manufacturing method that suppresses the breakage of the magnet can be constructed.

In the method of manufacturing a surface magnet type motor having the above steps, the step (b) includes: (b 1) pressing a magnet into the inside of the anti-scattering tube, and projecting each from both end faces of the magnet (B 2) attaching the assembly flange to the projecting part and holding the anti-scattering tube between the assembling flanges; (b 3) (b 2), after the process, The rotary shaft and the bearing may be attached to the anti-scattering tube, and an axial force in the rotational axis direction may be applied to the anti-scattering tube via the bearing, and it may be attached to the surface magnet motor housing. .

According to this manufacturing method, when attaching the rotor to the housing, an axial force in the direction of the rotational axis is applied to the anti-scattering tube via the bearing. Therefore, even if the anti-scattering tube is bent in the inward direction, this can be improved by the assembly to the housing.

In the method of manufacturing a surface magnet type motor having the above steps, the step (b) is

(b 1 1) A step of pressing a magnet into the inside of the anti-scattering tube to form protruding portions respectively protruding from both end faces of the magnet, and (b 1 2) applying an axial force in the rotational axis direction to the anti-scattering tube Attaching the assembly flange to the projecting part and fixing it while attaching, After the (13) (b 12) process, attach the rotating shaft and the bearing to the anti-scattering tube to which the axial force is applied. And a step of attaching to the housing of the surface magnet type motor.

According to this manufacturing method, when the assembling flange is attached to the anti-scattering tube into which the magnet is press-fitted, an axial force in the rotational axis direction is applied to the anti-scattering tube. Therefore, if the anti-scattering tube is bent in the radial direction, this can be improved in advance. In the method of manufacturing a surface magnet type motor having the above steps, the step (b) is

(b 2 1) sandwiching the magnet from both ends with the assembly flange, (b 2 2) integrally pressing the magnet and the assembly flange into the anti-scattering tube, (b 2 3) (b 2) 2 2) After the process, the rotary shaft and the bearing may be attached to the anti-scattering tube and attached to the housing of the surface magnet type motor. According to the strong manufacturing method, the magnet and the two assembly flanges are integrally press-fit into the anti-scatter tube. Therefore, the number of processes can be reduced and the rotor can be assembled efficiently, as compared to the case where the assembly flanges are press-fitted from both ends of the anti-scattering tube after the magnets are press-fitted.

In the method of manufacturing a surface magnet type motor having the above steps, the step (b) is (b 3 1) With the magnet applied with an axial force in the direction of the rotational axis, sandwiching the magnet from both ends with an assembly flange; (b 3 2) A magnet with applied axial force and an assembly flare (B 3 3) Attach the rotating shaft and the bearing to the anti-scattering tube equipped with the magnet and the assembly flange, and mount it on the surface magnet type motor housing. It may be made up of a process.

According to the strong manufacturing method, an axial force in the direction of the rotation axis, that is, a compressive force is applied to the magnet itself, and it is incorporated in the housing in that state. Therefore, in addition to the effects of the third manufacturing method, it is possible to control the necking and spreading deformation of the magnet in the press-in process, that is, to suppress the tensile stress and to reduce the breakage of the magnet.

The step (b 3 1) of the method of manufacturing a surface magnet type motor having the above steps is a step of applying an axial force by passing an assembly bolt through a magnet and an assembly flange and tightening an assembly nut. As well.

According to this manufacturing method, it is possible to easily apply an axial force to the magnet itself by the fastening force of the assembly bolt and the assembly nut.

An internal combustion engine provided with a surface magnet type motor according to the present invention is an internal combustion engine provided with a turbocharger having a turbine shaft, and a surface magnet type motor provided with a magnet on the surface of a rotor. The surface magnet type motor is formed in a cylindrical shape longer than the axial length of the magnet provided on the rotor, and includes a scattering prevention tube into which the magnet is press-fitted to prevent the magnet from scattering. And a stress relieving portion for relieving stress generated at an end of a magnet press-fit into the anti-scattering tube, wherein the surface magnet motor is coaxially provided with the turbine shaft.

According to the internal combustion engine of the present invention, the surface magnet type motor which relieves the stress generated at the end of the magnet is disposed coaxially with the turbine shaft for assisting the turbine shaft. Since the surface magnet type motor is in a state where the stress applied to the magnet is relaxed, the surface magnet type motor can sufficiently withstand large centrifugal force when it rotates with the high-speed rotating turbine shaft. Therefore, it can be disposed coaxially with the high-speed rotating turbine shaft, and an internal combustion engine with a supercharger equipped with an assist motor can be configured relatively easily. Brief description of the drawings

FIG. 1 is a schematic configuration view showing a cross section of a first surface magnet type motor of the present invention. FIG. 2 is a cross-sectional view showing the structure of the anti-scattering tube of the first embodiment.

FIG. 3 is a schematic view schematically showing the inner diameter difference after press-fitting due to the difference between the conventional structure and the first embodiment.

FIG. 4 is a cross-sectional view showing an example of the anti-scattering tube.

FIG. 5 is a cross-sectional view showing the structure of the anti-scattering tube of the second embodiment.

FIG. 6 is a schematic view schematically showing how a magnet is pressed into the anti-scattering tube of the second embodiment.

FIG. 7 is a cross-sectional view showing an example of the anti-scattering tube.

FIG. 8 is a schematic view of a second surface magnet type motor according to the present invention.

FIG. 9 is a process diagram showing an assembly process of a rotor as a method of manufacturing a motor. FIG. 10 is a cross-sectional view showing a part of the structure of the contact portion of the first embodiment.

FIG. 11 is a cross-sectional view showing a part of the structure of the contact portion of the second embodiment.

FIG. 12 is a cross-sectional view showing an example of the structure of the contact portion.

FIG. 13 is a cross-sectional view showing a part of the structure of the contact portion in the third embodiment.

FIG. 14 is a process diagram showing an assembly process of a rotor.

FIG. 15 is a cross-sectional view showing a part of the structure of the contact portion of the modification.

FIG. 16 is a process diagram showing an assembly process of a rotor.

FIG. 17 is a process diagram showing an assembly process of a rotor.

FIG. 18 is a configuration diagram showing a schematic configuration of a system provided with a surface magnet type motor in a turbocharged engine. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described in the following order based on examples.

A. First Motor Configuration:

A-1: First embodiment of shatterproof pipe:

A-2 2. Second Embodiment of Scattering Prevention Pipe:

B. Second motor configuration: B- l. First Embodiment of Contact Portion Structure:

B-2. Second Embodiment of Contact Portion Structure:

B- 3. Third embodiment of contact portion structure:

C. Modified example:

A. First Motor Configuration: '

FIG. 1 is a schematic configuration view showing a cross section of a first surface magnet type motor of the present invention. As shown, the first surface magnet type motor 10 (hereinafter simply referred to as the motor 10) is mainly a rotor 15 which is a rotating part of the motor 10 and a fixed part of the motor 10 fixed It comprises a rotor 12 and bearings 13 and 14 for fixing the rotor 15 to the housing of the motor 10. In this motor 10, a magnet 16 is provided on a rotor 15 and a winding for generating an electromagnetic force is provided on a stator 15. The rotating torque is generated by the magnet 16 that is repelled by the electromagnetic force. . The motor 10 is used to assist the turbine shaft in conjunction with the turbine shaft of a turbocharged vehicle (see FIG. 18), and the rotational speed of the rotor 15 is several hundreds of thousands rpm. .

In addition to the magnet 16, the rotor 15 is an assembly interposed between the rotary shaft 20 serving as the output shaft, the anti-scattering tube 17 for preventing breakage and scattering of the magnet 16 and the anti-scattering tube 17 and their respective bearings 13,14. Flanges 1, 8 and 19 are constructed.

The rotating shaft 20 rotates at high speed with the magnet 16, the shatterproof tube 17, the assembly flanges 18 and 19. The magnet 16 is made of a cylindrical sintered magnet and is subjected to a large centrifugal force by high speed rotation. The anti-scattering tube 17 has a substantially cylindrical shape, and is disposed on the outer periphery of the magnet 16 to prevent the magnet 16 from being damaged by the influence of the centrifugal force. The flanges 18 and 19 for assembly are in contact with the end face of the outer circumference of the circumferential portion 18 b and 19 b loosely fitted to the inner diameter of the anti-scattering pipe 17 and the end face of the anti-scattering pipe 17 and joined with the anti-scattering pipe 17 The outer circumferential portion 18c, 19c, and the outer circumferential portion 18d, 19d of the bearing 1 3, 14 that abuts on the outer circumference of the magnet. An inner cylinder 18 e, 19 e having an inner diameter smaller than the inner diameter is provided. The rotating shaft 20 is held by this inner cylinder. In addition, since the anti-scattering tube 17 is disposed between the magnet 16 and the stator 12, that is, in the rotating magnetic field, the anti-scattering tube 17 is formed of a nonmagnetic material that avoids the influence, for example, titanium stainless steel. There is. The rotor 15 having such a configuration is fixed by pressing the magnet 16 into the anti-scattering tube 17 and fixing assembly flanges 1 8 and 1 9 from both ends of the anti-scattering tube 1 7, It is assembled through the rotation shaft 20 to this. Fix the magnet 16 and the anti-scattering tube 17 by press-fitting with a large press-fitting cost. By doing this, the influence of the centrifugal force applied to the magnet 16 by high speed rotation is reduced. The anti-scattering tube 17 and the yarn erecting flanges 1 8 and 19 are fixed by aligning the core with a jig and welding the joint.

Bearings 13 and 14 are attached to the rotating shaft 20 of the assembled rotor 15. The bearings 13 and 14 use ball bearings with low rotational resistance, and have a structure that can withstand high-speed rotation. Thus, the motor 10 is formed by assembling the rotor 15 with the bearings 1 3 and 1 4 mounted in the housing of the motor 10 provided with the stator 1 2. The current flowing to the winding of stator 12 is supplied by an electric circuit (see Fig. 18).

A— 1. First Embodiment of Scattering Prevention Pipe:

FIG. 2 is a cross-sectional view showing the structure of the anti-scattering tube 17 of the first embodiment in which the magnet 16 is press-fitted. As shown, the titanium anti-scattering tube 17 is formed in a stepped cylindrical shape longer than the length of the magnet 16, and the magnet 16 is disposed near the approximate center of the stepped cylindrical shape. The anti-scattering tube 17 has a cylindrical portion 17a in which the magnet 16 is located (arranged), and a projecting portion 17b located at each end of the cylindrical portion 17a and projecting from the respective end faces of the magnet 16 It consists of three major parts: 1 7 c. By providing such projecting portions 17 b and 17 c, even if the internal magnet 16 is broken, it is possible to prevent the fragments from scattering to the outside.

The inner diameters of the cylindrical portion 17 a and the protruding portions 17 b and 17 c are the same diameter, and are processed to be smaller than the outer diameter of the magnet 16. In this way, the magnet 16 and the anti-scattering tube 17 are fixed without causing relative slippage even at high speed rotation by giving a predetermined interference (press-in allowance) and pressing. The protruding portions 17 b and 17 c have a cylindrical shape thinner than the cylindrical portion 17 a and have a shape lower in rigidity than the cylindrical portion 17 a. That is, the protruding portions 17 b and 17 c are portions that are more easily deformed (elastically deformed) than the cylindrical portion 17 a. In the present embodiment, the outer periphery of the anti-scattering tube 17 is A Φ SO (30 mm) is used, and a 0.1 mm interference allowance is provided as a press-in allowance, and a pressure input of several tons is applied to fix the magnet 16 and the anti-scattering tube 17.

When the magnet 16 is pressed into the anti-scattering tube 17, the anti-scattering tube 17 receives a reaction force from the magnet 16 and deforms (expands) within the elastic range. The cylindrical portion 17a of the anti-scattering tube 17 remains expanded because of the presence of the magnet 16, and the protruding portions 17b and 17c do not have the magnet 16 therein, but It deforms due to its low rigidity. That is, the projecting portions 17 b and 17 c are also expanded in inner diameter, and the difference in the inner diameter between the cylindrical portion 17 a and the projecting portions 17 b and 17 c after press-fitting can be reduced.

FIG. 3 is a schematic view schematically showing the inner diameter difference after press-fitting due to the difference between the conventional structure and the first embodiment. The conventional structure is shown in FIG. 3 (a), and the structure of the first embodiment is shown in FIG. 3 (b). The broken line in the figure shows the shape of the magnet 16 before press-fitting. As shown in FIG. 3 (a), the projecting portions A2 and A3 of the conventional construction of the anti-scattering tube A that project from the end face of the pressed-in magnet 16 are cylindrical portions A 1 where the pressed-in magnet 16 is present. It has the same cylindrical shape and is relatively rigid. Therefore, the protruding parts A2 and A3 are not easily deformed, and the inner diameter difference D is generated after the magnet 16 is press-fitted. A bending moment M0 is generated at the end of the magnet 16 due to this inner diameter difference.

On the other hand, as shown in FIG. 3 (b), in the anti-scattering tube 17 of the first embodiment, the inner diameter change of the projecting portions 17b and 17c becomes large compared to the conventional structure, and the inner diameter difference d d <D) has occurred. Therefore, no excessive bending stress (bending moment M0) is generated at the end of the magnet 16 by the reaction force from the protruding portions 17 b and 17 c, and almost no breakage occurs. In other words, the bending stress generated at the end of the magnet 16 due to the press-fitting can be alleviated by the deformation of the protruding portions 17 b and 17 c of the anti-scattering tube 17. As a result, it is possible to suppress the breakage of the magnet 16 when press-fitting, or when assembling as the rotor 15 after press-fitting or when using as the motor 10. In addition, by forming the anti-scattering tube 17 in a stepped cylindrical shape, the protruding portions 17 b and 17 c can be made low in rigidity, and the shape for relieving stress on the magnet 16 is a relatively simple shape. Can be realized by The shape of the anti-scattering tube that exerts such an effect is not limited to the stepped cylindrical shape, and for example, the outer cylinder may be processed into a tapered shape to make the change in section smooth. When processing into a taper shape, the length of the taper is not particularly limited, but it is different from a simple C chamfering and for the purpose of low rigidity, set the length equivalent to the length of the protruding part Is desirable. In this way, if the thickness of the outer cylinder of the protruding part is eliminated (or the thickness of the inner cylinder is eliminated) to make the rigidity low, various shapes can be assumed to suppress the breakage of the magnet 16.

FIG. 4 shows an example of the anti-scattering tube provided with a low-rigidity protruding portion. As shown, the anti-scattering tube 27 has a cylindrical shape substantially similar to that of the anti-scattering tube 17 shown in FIG. 2, and the anti-scattering tube 17 shown in FIG. The shapes of the projecting portions 2 7 b and 2 7 c which protrude from the end face of the magnet 16 are different. This scattering prevention pipe

The protruding portions 2 7 b and 2 7 c of 2 7 are provided with notches having a predetermined width and a predetermined depth all around. By providing such a notch, the same effect can be obtained even if the protruding portions 27 b and 27 c have low rigidity. In addition, it is possible to form the low rigidity protruding portions 27 b and 27 c by relatively easy processing.

A-2 2. Second Embodiment of Scattering Prevention Pipe:

In the first embodiment, although the projecting portions 17 b and 17 c have low rigidity and have a shape to suppress the inner diameter difference, the projecting portions 17 b and 17 c need to have low rigidity. Absent. FIG. 5 is a cross-sectional view showing the structure of an anti-scattering tube as a second embodiment in which the magnet 16 is press-fitted. As shown in the figure, the anti-scattering tube 37 has three cylindrical portions 3 7 a as in the first embodiment, and protruding portions 3 7 b and 3 7 c protruding from the end face of the pressed-in magnet 16. It consists of parts.

The protruding portions 3 7 b and 3 7 c are formed in a trumpet shape in which the inner diameter and the outer diameter are gradually expanded from the cylindrical portion 3 7 a side toward the end of the anti-scattering tube 3 7. Therefore, unlike the first embodiment, the protruding portion 3 7 b, compared to the cylindrical portion 3 7 a

3 7 c is highly rigid.

FIG. 6 is a schematic view schematically showing how the magnet 16 is press-fitted into the anti-scattering tube 37 of the second embodiment. As shown in the drawing, when the magnet 16 is press-fit into the anti-scattering tube 37 in the shape shown by the broken line and given a predetermined press-fit margin, the cylindrical portion 3 7 a corresponds to the first embodiment Similarly, since the magnet 16 is present inside, the change in inner diameter is large, and the protruding portions 3 7 b and 3 7 c have high rigidity, so the influence of the cylindrical portion 3 7 a is small and the change in inner diameter is small . That is, the difference with the inner diameter of the cylindrical portion 3 7 a after press-fitting can be reduced by expanding the inner diameters of the protruding portions 3 7 b and 3 7 c in advance. In Fig. 6, the inner diameter of the cylindrical portion 3 7 a after press-in and the protruding portion 3 after press-in

The inner diameters of 7 b and 3 7 c show almost the same diameter.

By predicting the change in the inner diameter of the anti-scattering tube 3 7 after press-fitting, by setting the inner diameter shape of the protruding portions 3 7 b and 3 7 c of the anti-scattering tube 3 7, the entire anti-scattering tube 3 7 The inner diameter difference can be suppressed. As a result, no excessive bending stress is generated at the end of the magnet 16 and almost no breakage occurs. In addition, the rigidity of the projecting portions 3 7 b and 3 7 c is not reduced.

The shape of the protruding portion may be, for example, the outer shape shown in FIG. 7 as long as it has a structure in which the inner diameter is expanded in advance. The shatterproof pipe 47 shown in the drawing is a cylindrical shape having three parts, all of which have the same outer diameter as in the first embodiment. Of these three parts, the cylindrical part 4 7 a has the same inside diameter as the first embodiment. On the other hand, the inside diameter of the protruding parts 4 7 b and 4 7 c protruding from the end face of the pressed-in magnet 16 is formed in a tapered shape 4 7 d gradually enlarged in diameter from the cylindrical part 4 7 a side to the outside. Teru. By pressing the magnet 16 into the anti-scattering tube 47, the same effect as the second embodiment can be obtained. Here, unlike the taper provided for positioning at the time of simple press-fitting, a tapered shape 4 7 d is provided over the entire length of the protruding portions 4 7 b and 4 7 c.

B. Second motor configuration:

FIG. 8 is a schematic view of a second surface magnet type motor according to the present invention. As shown, the second surface magnet type motor 21 (hereinafter simply referred to as the motor 21) basically has the same configuration as the first surface magnet type motor 10 shown in FIG. Only rotor 2 5 is different. Therefore, the other parts are given the same reference numerals as in FIG. 1 and the description is omitted.

As shown in FIG. 8, the rotor 25 is mainly composed of a rotary shaft 20, a magnet 16 and a shatterproof tube 17 which are similar to the first motor 10, and flanges 2 8 and 29 for assembly. Consists of ing.

The assembly flanges 2 and 2 9 are substantially the same as the assembly flanges 1 8 and 1 9 in the first motor 10, with the portions of the circumferential outer shape 2 8 b, 2 fitted to the inside diameter of the anti-scattering tube 1 7 9 b and a portion 2 8 d, 2 9 d of a circumferential outer shape that abuts the inner ring of the bearing 1 3, 1 4, and further, a specially shaped contact portion 2 8 contacting the anti-scattering tube 1 7 c 2 9 c is included. Inside the assembling flanges 2 8 and 2 9, inner cylinders 2 8 e and 2 9 e having an inner diameter larger than the threading flanges 1 8 1 and 19 of the first embodiment are provided. That is, the assembly flanges 2 8 and 2 9 are slidably in contact with the rotation shaft 20 in the axial direction. The alignment of the flanges for assembly 2, 8 and 9 with the anti-scattering tube 17 is carried out by the portions 2 8 b and 2 9 b of the outer diameter of the cylinder. The specially shaped portions 2 8 c and 2 9 c of the assembling flanges 2 8 and 2 9 will be described later as the contact portion structure of the assembling flanges 2 8 and 2 9.

The rotor 25 composed of such parts is assembled by the procedure shown in FIG. FIG. 9 is a process chart showing an assembly process of the rotor 25 as a method of manufacturing the motor 21. As shown, first, the magnet 16 is pressed into the anti-scattering tube 17 (step S 900). Subsequently, the anti-scattering tube 17 provided with the magnet 16 is sandwiched from both ends by the flanges 8 and 2 9 for threading, and the rotating shaft 20 is attached (step S 9 10).

In this state, the bearings 1 3 and 1 4 are fitted to the rotary shaft 20, and an axial force F in the direction of the rotary shaft 20 is applied to the assembly flanges 2 8 and 2 9 via the bearings 1 3 1 4 Then, as it is fixed in the housing of the motor 21 provided with the stator 12 (step S 920), the assembly of the rotor 25 is completed. After assembling the rotor 25, the motor 2 1 is completed through a predetermined process. In addition, since the assembling flanges 2 and 2 9 of the rotor 25 assembled according to the above procedure are in contact with the inner rings of the bearings 1 and 3, the magnets 16 and the anti-scattering tube 17 and the standing flanges 2 8, 2 9 and the rotation shaft 20 rotate integrally. The inner rings of the bearing supports 1 3 and 1 4 and the assembly flanges 2 and 2 9 are fixed by means of a rotation stopper (not shown).

B-1 1. First embodiment of contact part structure:

The assembling flanges 2 8 and 2 9 and the anti-scattering tube 17 shown in FIG. 8 are provided with contact portions 2 8 c and 2 9 c of special shapes, respectively. Figure 10 shows the structure of this contact It is sectional drawing which expanded and represented a part of manufacturing. As shown in the drawing, the assembling flange 28 is provided with a convex portion 2 8 a having substantially the same outer diameter as the anti-scattering tube 17. In addition, as a result of forming the projecting portion 17 b in the anti-scattering tube 17 in a stepped cylindrical shape, a stepped shoulder 17 d is formed on the stepped portion of the outer periphery of the cylinder. In the contact portion structure according to the first embodiment, the convex portion 2 8 a and the stepped shoulder portion 1 7 d are in contact with each other, and the end face of the flange 2 8 for assembly and the protruding portion 1 7 b is directly Do not touch Although not shown, a contact portion symmetrical to the bearing 13 side shown in FIG. 10 is also provided on the bearing 14 side.

As described above, an axial force F (compression force) is externally applied to the assembly flange 28 having such a contact portion structure and the anti-scattering tube 1 (including the magnet 16) at the time of assembly. . The applied axial force F is transmitted as an axial force f near the outer periphery of the anti-scattering tube 17 via the convex portion 2 8 a of the assembly flange 2 8 (see the arrow in FIG. 10). The axial force f applied to the vicinity of the outer periphery of the anti-scattering tube 17 is a moment M 1 which pushes and spreads the inner cylinder of the anti-scattering tube 17. The moment M l acts in a direction to reduce the bending moment M O generated in the projecting portions 17 b and 17 c of the splash prevention tube 17 by the press-fitting of the magnet 16. In other words, as shown in FIG. 3 (a), a force acts in the direction to improve the bending of the anti-scattering tube A in which the protruding portions A 2 and A 3 are bent inward by press-fitting. Therefore, in addition to the effect due to the shape of the projecting portions 17 b and 17 c described in the first embodiment of FIG. 3 (b), the difference in the inner diameter displacement of the anti-scattering tube 17 is further reduced, The bending stress to 16 can be relieved. In this embodiment, about half of the thickness of the anti-scattering tube 17 (peripheral side) is in contact, but the contact position is closer to the outer cylinder than the inner cylinder of the anti-scattering tube 17 (peripheral side If it is), it produces the same effect. In addition, the structure of such a contact portion may be any structure as long as it acts in the direction to reduce the bending moment M O (see FIG. 3) generated in the axial force F force anti-scattering tube to be applied. Another structure of such a contact portion is shown below.

B-2 2. Second embodiment of contact part structure:

FIG. 11 is a cross-sectional view showing a part of the structure of the contact portion between the assembly flange and the anti-scattering tube as a second embodiment. Figure 11 shows only the bearing 1 3 side as the contact part structure, but there is also a contact part structure symmetrical to the bearing 1 3 side also on the bearing 1 4 side It is similar to Figure 10.

As shown in the figure, the contact portion of the anti-scattering tube 57 is provided with an axially projecting convex portion 5 7 a near the outer periphery of both ends of the cylindrical shape, and the contact portion of the assembly flange 38 is flat 3 8 a is provided. That is, the axial force F applied from the outside is applied as the axial force f to the convex portion 5 7 a of the anti-scattering tube 5 7 through the inner ring of the bearing 1 3 and the flat surface 3 8 a of the assembly flange 3 8. (See the arrow in Figure 11). Therefore, as in the first embodiment, the bending moment M 0 generated in the anti-scattering tube 5 7 is reduced by the axial force f applied to the vicinity of the outer periphery of the anti-scattering tube 5 7 to suppress the inner diameter displacement difference. It can relieve bending stress.

Such a convex portion 5 7 a provided only on the side of the anti-scattering tube 5 7 may be provided only on the side of the assembly flange 4 8 as shown in FIG. 12. In this case, as shown in the drawing, the flange 4 8 for assembly is provided with a convex portion 4 8 a, and unlike the structure shown in FIG. 10, it is not necessary to provide the anti-scattering tube with a special shape.

B-3. Third Embodiment of Contact Portion Structure:

FIG. 13 is a cross-sectional view showing a part of the structure of the contact portion between the assembly flange and the anti-scattering tube according to the third embodiment. Although only the bearing 13 side is shown in FIG. 13 as the contact portion structure, it is the same as FIG. 10 that there is a contact portion structure symmetrical to the bearing 13 side also on the bearing 14 side.

As shown in the figure, a tapered portion 6 7 a whose diameter is increased from the end face of the magnet 16 toward the end face of the scattering prevention pipe 6 7 is provided at the contact portion of the scattering prevention pipe 67, and the flange for assembly The contact portion 58 is engaged with the tapered portion 6 7 a and has an engagement portion 5 8 a longer than the tapered portion 6 7 a. That is, the engaging portion 5 8 a of the assembling flange 5 8 is a structure that enters into and contacts the inside of the anti-scattering tube 67.

In the contact portion structure of the third embodiment, when an axial force F is applied from the outside, the engagement portion 5 8 a of the assembly flange 5 8 gets into the inside of the anti-scatter tube 6 7 and splashes due to a so-called creep effect. Push and expand the inside diameter of the end of the prevention pipe 67. That is, the axial force F is replaced with a force P in the radial direction. Such a structure makes it possible to reduce the difference in the inner diameter displacement of the anti-scattering tube 67 and to relieve the bending stress on the magnet 16. Also, due to the wedge effect, the alignment between the assembly flange 58 and the anti-scattering tube 67 is also possible. It becomes easy.

In the second electric motor 21 described above, an axial force F is applied at the time of assembly to the housing, and the axial force F reduces the difference in the inner diameter change due to the press fit of the anti-scattering tube and reduces the bending stress applied to the magnet 16. Do. Therefore, the axial force F can improve this even if the anti-scattering tube is bent before being assembled to the housing. The process of applying the axial force F may be performed before assembling the housing, that is, the scattering prevention pipe and the assembly flange may be assembled first while applying the axial force F.

FIG. 14 is a process diagram showing an assembly process of the rotor 25 as a method of manufacturing the motor 21. As shown in the figure, first, the magnet 16 is pressed into the anti-scattering tube 17 (step S 400). Subsequently, the anti-scattering tube 17 with the magnet 16 is held from both ends by the assembly flanges 2 8 and 2 9, and the assembly flanges 2 8 and 2 9 are scattered with the axial force F applied from both ends. Fix the prevention pipe 17 by welding (Step S 4 1 0). The rotary shaft 20 and bearings 1 3 and 1 4 are mounted on the assembly with the compressive stress remaining inside in this way, assembled in the housing (step S 4 2 0), and the rotor 2 5 assembled To complete. Even if the process of applying such an axial force F is performed before threading to the housing, the effect of reducing the bending stress to the magnet 16 is exerted. In addition, the bending of the anti-scattering tube can be improved in advance.

C. Modified example:

In the third embodiment (FIG. 13) of the second electric motor 21 according to the present invention, the inner diameter of the end of the anti-scattering tube 67 is expanded by utilizing the taper shape. Instead of the inclined surface, a flat shape, that is, a portion of the assembling flange that enters the anti-scattering tube may be simply formed in a cylindrical shape. This structure is described below.

FIG. 15 is a cross-sectional view showing a portion of the structure of the contact portion between the assembly flange and the anti-scattering tube as an alternative example. As shown, the contact portion of the assembly flange 68 is provided with a cylindrical portion 6 8 a substantially the same as the outer diameter of the magnet 16. On the other hand, the contact portion of the anti-scattering tube 7 7 does not have a special structure, and remains cylindrical with a press-in allowance for press-fitting the magnet 16. Also in this modification, as in FIGS. 1 1 and 13, the structure of only the bearing 13 side is shown, and the structure of the bearing 14 side is omitted.

In this contact portion structure, the axial force F from the outside is press-fit onto the assembly flange 68 Force Apply FA. By this pressure input FA, the cylindrical portion 6 8 a of the assembly flange 6 8 is pushed in and disposed at both ends of the anti-scattering tube 7 7. In this contact part structure, the force P in the direction to expand the inside diameter of the end of the anti-scattering tube 7 is applied by press-fitting the flange for assembly 68 into the entire length of the anti-scattering tube 7! : Reduce the displacement difference in the inner diameter direction. Therefore, bending stress applied to the magnet 16 can be relieved.

In such a contact portion structure, since the outer diameter shapes of the magnet 16 and the assembly flange 68 are substantially the same, the pressure input of the anti-scattering tube 77 to the magnet 16 can be used. FIG. 16 is a process diagram showing an assembling process of the rotor having the contact portion structure shown in FIG. As shown in the figure, first, the magnet 16 is sandwiched from both ends by the assembly flanges 6 8 and 6 9 (step S 600). It is good if sandwiching by the assembly flanges 6 8 and 6 9 is made integral using jigs and adhesives.

Subsequently, an assembly in which the assembly flanges 6 8 and 6 9 and the magnet 16 are integrated is pressed into the anti-scattering tube 7 7 (step S 6 10). By this press-in, the magnet 16 is placed as it is up to the end of the anti-scattering tube 77. In other words, the inside diameter of the end of the shatterproof tube 7 (the part corresponding to the protruding parts 17 b and 17 c described in the first motor 10) is the part where the magnet 16 is disposed inside The diameter is expanded in the same manner. The rotary shaft 20 is screwed into the inner cylinder of the standing flanges 6 8 6 9 and magnet 1 6 thus fixed to the anti-scattering tube 7 7 and assembled in the housing together with the bearings 1 3 Step S 620) Complete the assembly of the rotor. By using such a manufacturing method, it is possible to assemble the rotor in a single press-in process without applying many pressure inputs. Therefore, an efficient rotor manufacturing method with a reduced number of processes can be realized. .

In addition, the clamping force by the port and the nut may be used for clamping by the assembly flanges 6 8 and 6 9 in step S 600. FIG. 17 is a process diagram showing an assembly process of a rotor having the contact portion structure shown in FIG. As shown in the drawing, the assembly port 90 was inserted through the magnet 16 and the flanges 8 8 for rooting, and tightened with the assembly nut 91 to apply a compression force to the magnet 16 by the fastening force. In the state, sandwich with the assembly flanges 6 8 and 6 9 (step S 7 0 0).

Press the assembly that has been integrated in this way into the anti-scattering tube 77 and fix it. Tep S 7 1 0). In this step, the assembly flanges 6 8 and 6 9 and the magnet 16 under compression are fixed to the anti-scattering tube 7 7.

Then, remove the mounting bolt 90 and the assembly nut 91 by using the magnet 16 fixed by press fitting, the assembly flange 68, 69 force, and instead, attach the rotary shaft 20. Then, assemble them together with the bearings 1 3 and 1 4 in the housing (step S 7 2 0) to complete the assembly of the rotor.

By using such a manufacturing method, it is possible to reduce the difference in displacement in the radial direction of the anti-scattering tube 77 and to relieve the bending stress on the magnet 16. Furthermore, by applying a compressive force to the magnet 16 itself, it is possible to suppress the bending stress (tensile stress due to bending) acting on the entire magnet 16.

The surface magnet type motor described above is used to assist the rotation of the turbine shaft in a turbocharged engine. FIG. 18 is a configuration diagram showing a schematic configuration of a system provided with a surface magnet type motor on an engine having a turbocharger as a supercharger.

As shown, the system mainly includes an engine 100 with an intake pipe 101 and an exhaust pipe 102, and wheels with an intake pipe 101 and a trachea 102. Control the entire system such as a turbocharger 1 1 0, a surface magnet type motor 1 2 0 coaxially arranged with the turbocharger 1 1 0, an inverter 1 3 0, an engine 1 0 0 and a turbo charger 1 1 0 It consists of ECU 140 and so on. Here, the surface magnet type motor 120 may be the first motor 10 or the second motor 21.

In this system, the turbine wheel, which is the wheel on the side of the trachea 102, is rotated by the energy of the exhaust gas discharged from the engine 100, and the motive power is used to drive the compressor wheel, which is the wheel on the intake pipe 101 side. Rotate. In this way, compressed air can be supplied to the engine 100 to increase the charging efficiency. In this system, a surface magnet type motor 120 is provided to forcibly rotate a turbine shaft connecting a turbine wheel and a compressor wheel when exhaust energy is not sufficient. The power to the surface magnet type motor 120 is supplied via the inverter 130 under the judgment of the ECU 140. Note that The exhaust pipe 102 is provided with a bypass that bypasses the turbine wheel, and a waste gate valve 115 is disposed near the inlet of the bypass. When supercharging is not necessary, control is performed to open the waste gate valve 115.

Generally, as a system equipped with an electric motor used for assisting a turbine shaft that requires high-speed rotation, such as a system that arranges an electric motor on an axis provided separately from the turbine shaft and transmits power to the turbine shaft, a one-way clutch, etc. It is conceivable to provide a system that prevents corotation with the turbine shaft. By adopting such a system, the allowable rotational speed of the motor can be kept low. However, it is difficult to construct a power transmission mechanism or one wheel clutch corresponding to a turbine shaft operating at hundreds of thousands of revolutions, and the reality of such a system is difficult. On the other hand, the surface magnet type motor of the present invention can cope with high speed rotation, and can be disposed coaxially with the turbine shaft for assisting the turbine shaft. That is, the surface magnet type motor of the present invention can be relatively easily adapted to a system requiring high speed rotation.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be embodied in various forms without departing from the scope of the present invention. . In this embodiment, the structure of the protruding portion of the anti-scattering tube, the application of axial force to the anti-scattering tube, and the application of compressive force to the magnet itself, the structure for reducing the stress applied to the magnet, the manufacturing method, etc. As described above, the same effect can be obtained by using a combination of such various structures and manufacturing methods.

Claims

The scope of the claims

1. A surface magnet type motor comprising magnets on the surface of a rotor,

It is formed in a cylindrical shape longer than the axial length of the magnet provided on the rotor, and includes an anti-scattering tube into which the magnet is press-fitted to prevent the magnet from scattering.

A stress relieving portion is provided for relieving stress generated at the end of the magnet pressed into the anti-scattering tube.

Surface magnet type motor.

2. A surface magnet type motor according to claim 1, wherein

The stress relieving portion is a part of the anti-scattering tube, and is provided on protruding portions respectively protruding from both end faces of the pressed-in magnet, and an inner diameter generated in the protruding portion and the portion excluding the protruding portion by the press-fitting. A surface magnet type motor that has a shape that suppresses the difference in directional displacement.

3 · The surface magnet type motor according to claim 2, wherein

The surface magnet type electric motor, wherein the stress relieving portion has a shape in which the difference is suppressed by making the protruding portion lower in rigidity than a portion excluding the protruding portion.

4. A surface magnet type motor according to claim 3, wherein

In the surface magnet type motor, the shape for suppressing the difference has a low rigidity by making the protruding portion thinner than the portion excluding the protruding portion.

5. A surface magnet type motor according to claim 3, wherein

The surface magnet type electric motor having a low rigidity by forming a notch of a predetermined depth in the outer cylinder of the protruding portion to suppress the difference.

6. A surface magnet type motor according to claim 2, wherein

The surface magnet type electric motor, wherein the stress relieving portion has a shape in which the difference is suppressed by making the cylindrical inner diameter of the protruding part larger in diameter than the cylindrical inner diameter of the part excluding the protruding part.

7. A surface magnet type motor according to claim 2, wherein

The surface magnet type electric motor, wherein the stress relieving portion has a shape in which the protruding portion is expanded in a trumpet shape to suppress the difference.

8. A surface magnet type motor according to claim 1, wherein

An assembly flange is provided between the bearing attached to the rotating shaft and each end face of the magnet,

The stress relieving portion is provided at a contact portion where the protruding portion which is a portion of the anti-scattering tube protruding from each end face of the pressed-in magnet and the assembling flange contact each other, and the assembling flange A surface magnet type electric motor having a shape that suppresses a difference in displacement in an inner radial direction generated in the protruding portion and a portion excluding the protruding portion by the press-in by applying external force in the rotational axis direction from both outer sides of the.

9. A surface magnet type motor according to claim 8, wherein

The surface magnet type electric motor having a shape in which the contact portion is configured to convert an external force from the assembly flange into an axial force applied to an outer peripheral side of an inner periphery of the anti-scattering tube.

10. The surface magnet type motor according to claim 9, wherein

A magnet type electric motor having a convex shape in which the contact portion of the anti-scattering tube is in contact with the yarn and flange at the outer peripheral end face of the anti-scattering tube.

11. The surface magnet type motor according to claim 9, wherein

The surface magnet type electric motor which made the contact part of the said flange for assembly the convex shape which contacts the outer peripheral side end surface of the said anti-scattering pipe.

The surface magnet type motor according to claim 9.

The contact portion of the anti-scattering tube is formed in a cylindrical shape which is smaller than the cylindrical outer diameter of the portion excluding the protruding portion, and the entire anti-scattering tube has a stepped cylindrical shape, and the contact of the flange for assembly The surface magnet type electric motor which formed the part in the shape which contact | connects the said shouldered shoulder part of the step shape cylindrical shape.

11. The surface magnet type motor according to claim 10, wherein

The surface magnet type electric motor, wherein the contact portion is shaped to convert an external force from the threading flange into a force in a direction in which an inner diameter of the protruding portion is expanded.

14. The surface magnet type motor according to claim 13, wherein

The contact portion of the anti-scattering tube is formed in a tapered shape in which the inner diameter of the protruding portion is expanded relative to the inner diameter of the portion excluding the protruding portion, and the contact portion of the assembly flange is engaged with the tapered shape. Surface magnet type electric motor formed in matching shape.

15. A surface magnet type motor according to claim 13, which is:

A surface magnet type electric motor in which a contact portion of the assembly flange is formed in a cylindrical shape which has substantially the same outer diameter as the magnet and which can be press-fit into a protruding portion of the anti-scattering tube.

16. A manufacturing method of a surface magnet type motor including a magnet on a surface of a rotor, wherein: (a) an anti-scattering tube which covers the surface of the magnet of the rotor to prevent scattering of the magnet; Forming in a cylindrical shape longer than the length;

(b) forming a stress relieving portion for relieving stress generated at an end of the magnet housed inside the anti-scattering tube, and pressing the magnet into the anti-scattering tube. Manufacturing method of magnet type motor.

17. A method of manufacturing a surface magnet type motor according to claim 16, which is:

In the step (b),

(b 1) press-fitting the magnet into the inside of the anti-scattering tube to form a projecting portion which protrudes from both end faces of the magnet;

(b 2) mounting an assembly flange on the projecting portion, and holding the anti-scattering tube with the assembly flange;

(b 3) After the step (b 2), the rotary shaft and the bearing are attached to the anti-scattering tube, and an axial force in the rotational axis direction is applied to the anti-scattering tube via the bearing. Attaching the housing to the housing of the surface magnet type motor.

A method of manufacturing a surface magnet type motor.

18. A method of manufacturing a surface magnet type motor according to claim 16, which is:

In the step (b),

(11) The step of pressing the magnet into the inside of the anti-scattering tube, and forming a protruding portion respectively protruding from both end faces of the magnet;

(b 12) attaching and fixing an assembly flange to the protruding portion while applying an axial force in the rotational axis direction to the anti-scattering tube;

(b13) after the step (b12), mounting the rotating shaft and the bearing on the anti-scattering tube to which the axial force is applied, and attaching the housing to the housing of the surface magnet type electric motor

A method of manufacturing a surface magnet type motor.

A method of manufacturing a surface magnet type motor according to claim 16.

In the step (b),

(b 2 1) sandwiching the magnet from both ends with an assembly flange;

(b 2 2) integrally pressing the magnet and the assembly flange into the anti-scattering tube;

(b 2 3) A method of manufacturing a surface magnet type electric motor, comprising the steps of: attaching the rotation shaft and the bearing to the anti-scattering tube after the step (b 2 2); and attaching it to a housing of the surface magnet type electric motor.

A manufacturing method of the surface magnet type electric motor according to claim 16 which is 2 0.

In the step (b),

(b 3 1) sandwiching the magnet from both ends with an assembly flange in a state where an axial force in the rotational axis direction is applied to the magnet;

(b 3 2) integrally pressing the magnet in a state in which the axial force is applied and the assembly flange into the anti-scattering tube;

(b 3 3) attaching the rotating shaft and the bearing to the anti-scattering tube provided with the magnet and the assembling flange, and attaching the housing to the housing of the surface magnet type motor

A method of manufacturing a surface magnet type motor.

21. A method of manufacturing a surface magnet type motor according to claim 20, wherein

A manufacturing method of a surface magnet type motor, wherein the step (b 3 1) is a step of passing an assembly bolt between the magnet and the assembly flange and applying an axial force by tightening an assembly nut.

2 2. An internal combustion engine equipped with a turbocharger having a turbine shaft,

A surface magnet type motor having a magnet on the surface of a rotor is provided as a motor for an assist of the turbine shaft,

The surface magnet type motor is

Stress relaxation that relieves the stress generated at the end of the magnet pressed into the anti-scattering tube To be configured

An internal combustion engine comprising the surface magnet type motor coaxially with the turbine shaft.